1. Field of the Invention
This invention relates to an ornament cap for casings, and more particularly, to an ornament cap for covering a designed groove formed in plastic casings such as computer display units.
2. Background of the Invention
Plastic casings for computer display units and the like are usually fastened together by means of latching or screwing. The latching method is usually used for small-size or light-weight casings. It generally makes use of a keyway, a snap hook, a latch pin and the like to fasten the casings together. On the other hand, for large-size or heavy-load casing devices, it is more reliable and preferable to fasten the plastic casings by screws or bolts. In order to accommodate the screws, a transverse screw groove is usually provided in the casing at the fastening area.
FIG. 1 shows a typical conventional fastening means for a computer display unit 1. The display unit 1 comprises a second casing 11 and a mating first casing 13 fastened together by means of a plurality of screws 15. In the first casing 13, there are a couple of wedge-shape grooves 17 for accommodating the screws 15 to transversely fasten the second casing 11. However, the wedge-shape grooves 17 on the first casing 13 are generally not artistic in appearance. Therefore, it is preferable to use ornament caps 10 to cover the wedge-shape grooves 17 and make the casing look smoother and more beautiful.
However, the ornament caps 10 according to the conventional art have no other functions than covering the grooves 17. Moreover, if the ornament caps 10 are held in the wedge-shape grooves 17 too tightly, the ornament caps 10 will be difficult to be released from the grooves 17 or easily be damaged by prizing when it is necessary to separate the second casing 11 from the first casing 13 (while interior repair is needed). On the other hand, if the ornament caps 10 are held in the wedge-shape grooves 17 too loosely, they will drop off from the grooves easily and lose their function.
The main object of the present invention is to provide an ornament cap for smoothing out the fastening grooves in the casings, particularly to the grooves for fastening two casings by means of screws.
It is another object of the present invention to provide a reliable fastening ornament cap that has a horizontal limiting means and a vertical limiting means for restricting positions in two separating directions of the cap so that the ornament cap may be securely held in the casing.
The ornament cap according to the present invention is used for covering a screw groove formed in a first casing which is fastened with a second casing by means of a transverse screw accommodated in the screw groove. The ornament cap includes a seat fixedly located in the screw groove and an insert to be engaged with the seat and to cover the screw groove. At the engaging interface between the insert and the seat, a horizontal limiting means and a vertical limiting means are provided.
The vertical limiting means has a limiting structure for preventing the insert from loosing away from the screw groove in a direction perpendicular to the first casing wall after the insert has been engaged with the seat.
The horizontal limiting means is for preventing the insert from separating from the screw groove in a direction parallel to the first casing wall after the insert has been engaged with the seat. The horizontal limiting means includes two elastic stability states. The first stability state defines the separation condition between the insert and the seat. The second stability state defines the engaging condition between the insert and the seat.
According to the present invention, when the insert is under the engaging operation with the seat and at the time the vertical limiting means forms a limiting position, the horizontal limiting means will jump from the first stability state to the second stability state to complete the engaging operation. On the other hand, when the insert is being separated from the seat, a force is firstly applied to the horizontal limiting means to make the horizontal limiting means switch from the second stability state to the first stability state. Thereafter, another transverse force is applied to make the vertical limiting means be separated so that the insert is separated from the seat.
In an embodiment of the present invention, the vertical limiting means may include a plurality of foot holes and the mating latch legs. The foot holes are through holes formed in the seat with selected length and width. The latch legs are located on the insert for engaging with the foot holes when the engaging operation of the insert and the seat takes place. Each latch leg further has a transverse foot for engaging with the first casing wall adjacent to the foot hole when the insert is being engaged with the seat to form a vertical limiting position for preventing the ornament cap from separating with the casing vertically.
In another embodiment of the present invention, the vertical limiting means may include a plurality of foot holes and the mating latch legs. The foot holes are through holes located in the insert with selected length and width, and connect to a passage extending in a direction opposite to the second casing. The latch legs are located in the seat and each leg has a foot extending in a direction opposite to the second casing for engaging with the passage through the foot hole to form a vertical limiting position.
In a further embodiment of the present invention, the screw groove may include at least one side wall and the insert includes a side wing mating with the side wall. The vertical limiting means may include at least one bump formed on the side wall and parallel to the lateral side of the first casing, and one bulged spot located on the side wing mating with the bump. The vertical limiting means is under engaging state when the bump is positioned between the first casing and the mating bulged spot. The vertical limiting means is under separating state when the bulged spot is positioned between the first casing and the mating bump.
In yet another embodiment of the present invention, the screw groove may include at least one side wall and the insert includes a side wing mating with the side wall. The vertical limiting means may include at least one bulged spot formed on the side wall and parallel to lateral side of the first casing, and a bump located on the side wing mating with the bulged spot. The vertical limiting means is under engaging state when the bump is positioned between the first casing and the mating bulged spot. The vertical limiting means is under separating state when the bulged spot is positioned between the first casing and the mating bump.
In an embodiment of the present invention, the horizontal limiting means may include at least one elastic latching member and a mating stopping arm. The elastic latching member, for example an elastic plate, is located in the seat and formed on a first casing wall in a cantilever manner which has a free end facing the second casing and a stopping nose facing the insert. The stopping arm is located in the insert to form a horizontal limiting position with the elastic latching member when the insert has been engaged with the seat. In other word, the stopping arm is located on the far side of the stopping nose from the second casing before the insert being engaged with the seat (first stable state). After the insert engages with the seat (second stable state), the stopping arm is located at another side of the stopping nose, i.e., near the second casing. When the stopping arm passes over the stopping nose, the stopping arm will press the stopping nose and store elastic potential energy in the elastic latching member. In a preferred embodiment, the stopping nose is wedge-shaped with a sloped surface facing the opposite side of the second casing.
In another embodiment of the present invention, the horizontal limiting means may include at least one elastic latching member and a mating stopping arm. The elastic latching member is a cantilever type elastic member extending horizontally from the bottom of the screw groove toward the second casing. It has a free end upon which a stopping nose facing the insert is located. The stopping arm is located in the insert to form a horizontal limiting position with the elastic latching member when the insert has been engaged with the seat. The stopping arm is located on the far side of the stopping nose from the second casing before the insert being engaged with the seat (first stable state). After the insert engages with the seat (second stable state), the stopping arm is located at another side of the stopping nose facing the second casing. According to a preferred embodiment, the stopping nose is wedge-shaped with a sloped surface facing the opposite side of the second casing.
In yet another embodiment of the present invention, the horizontal limiting means may include an elastic arm extending toward the second casing and a mating latch hole located in the first casing. The elastic arm has a stopping hook located at one end for engaging with the latch hole under an external force. When the insert and the seat are engaged, the elastic arm and the stopping hook return to original positions. It is under the second stable state.
In a further embodiment of the present invention, the horizontal limiting means may include at least one bump located on the seat and perpendicular to a first casing wall, and a mating bulged spot located on the insert. When the bump is positioned between the second casing and the mating bulged spot, the horizontal limiting means is under separation state (the first stable state). When the bulged spot is positioned between the second casing and the mating bump, the horizontal limiting means is under engaging state (the second stable state).
In still another embodiment of the present invention, the horizontal limiting means may include at least on bump located in the insert normal to a first casing wall, and a mating bulged spot located on the seat. When the bump is positioned between the second casing and the mating bulged spot, the horizontal limiting means is under separation state (the first stable state). When the bulged spot is positioned between the second casing and the mating bump, the horizontal limiting means is under engaging state (the second stable state).
In still yet another embodiment of the present invention, the insert has a view window mating against the horizontal limiting means that enables a hand tool to apply a force on the horizontal limiting means.